I updated my InDesign to the latest 2017.1 upon its release. Now, while reading David Blatner's review on the this latest update, he mentioned the new "New Document" dialogue window which shows Unit option to select Inches or Centimetres, he says this new window doesn't show intent drop menu beside other things.

My InDesign still showing the legacy "New Document" window, I went to the Preferences > General, I don't see the option that switches my InDesign to legacy. If you've updated to the latest copy, can you check to see if you have the new dialogue window!

If you are on Middle East(yes!)/North American language feature set for InDesign then the New Document which, as of now, is not available for your feature set. The preference that you have mentioned ("Use Legacy New Document Dialog") is to disable that "New dialog" and hence it is not visible to you.

Illustrator and Photoshop has provided the new dialog for Middle East but InDesign has yet to implement this feature for Middle east feature sets. As for now, you can try out the templates which are new in the "New Document Dialog" can be tried directly from Adobe Stock website. You can manage the InDesign templates in CC Libraries panel by selecting Stock Templates library.

In that same review, David Blatner also noticed that this 'better, improved' dialog got displayed glacially slow. Will that part of this new feature be faithfully copied to the ME version as well? And will it come with the same work-around "use legacy dialog" in the Preferences?